You've seen them.
The television commercials selling long-distance telephone companies with claims of cheaper rates, less hassle or better reliability than their competitors.
Actress Candice Bergen, for example, is selling U.S. Sprint Corp. -- the third-largest long-distance company -- on its rates, reliability and the fact that she is a customer.
There are other gimmicks.
Perhaps you found a $20 check in the mail. Free cash -- in exchange for switching your long-distance service to MCI Telecommunications Corp., the second-largest provider behind American Telephone & Telegraph Co. AT&T sells itself simply as "the right choice."
Or you answered your telephone one night to find a telephone company on the other end, offering to switch you to its service for a free tryout. No obligation.
And there are any number of newspaper and magazine advertisements promising money-saving discount calling plans, telephone credit cards or other services.
Faced with a bewildering array of companies and calling options, it is no wonder that even sophisticated consumers might be confused about which long-distance company is best for them, or even how to compare.
So which long-distance company is the best? Consumer advocates say there is no single answer.
"There is no 'best service' because everyone has individual needs," said Sylvia Rosenthal of the non-profit Alliance for Public Technology in Washington.
After the breakup of the Bell system in the mid-1980s, "AT&T offered quality, and the other companies offered price. That situation is equalized somewhat. There have been so many changes in recent years that the companies are pretty much all equal," said Ms. Rosenthal, former director of the Tele-Consumer Hotline, a non-profit service that answers consumers' questions about rates and services.
An annual survey by Consumer Action in San Francisco shows little difference in basic long-distance rates among AT&T, MCI XTC and U.S. Sprint, said Mark A. Foster, policy analyst for the non-profit education and advocacy group, which specializes in banking and telecommunications issues.
For most telephone customers who make less than $15 in out-of-state calls each month, the difference between the companies is so small that it almost doesn't matter which the customer chooses, Mr. Foster said.
A nationwide survey shows that the average monthly long-distance bill is $6.87, AT&T spokeswoman Robin Sayre said.
But it does make a difference if you make a lot of long-distance calls -- $25 or more a month -- or make most of them to the same calling area.
Organizations such as the Tele-Consumer Hotline and Consumer Action advise people to use a checklist to help them make the best choice.
Start by analyzing your calling patterns -- the number of calls you make each month, when you make them and where. Then compare the features, costs and quality differences between companies, said Terry Moody, a consumer counselor with the hot line.
Next, create a sample bill by picking out five or six out-of-state calls you make regularly. Make sure it reflects the typical length of your calls, and the amount you usually spend each month on long-distance calling. Note the day of the week and time of day the calls were made, their destinations and their length.
Now compare the features of your current long-distance company with at least two others. The hot line checklist suggests several areas to look at:
* Cost: The cost of a call isn't as simple as figuring out what the company charges per minute. You need to know how the company bills the length of the calls, every six seconds, every 30 seconds or rounded up to the next full minute.
Some companies charge a monthly minimum, especially for discount calling plans. Also, there may be a monthly service fee in addition to the cost of your long-distance calls.
* Restrictions: Direct-dial service may not be available for calls to other countries or overseas. Charges will vary. Find out whether long-distance directory assistance is available and what you will be charged for the call.
* Discounts: Some companies offer discounts for prompt payment of bills or for making a certain amount of calls per month. Make sure you know how the discount program works and any restrictions on the credits or merchandise awards.
After all this, call the long-distance companies. Ask what the company would charge for the specific calls on your list.
The last step is to test the quality of the companies' service by using their telephone lines and equipment. Each company is assigned a special five-digit access code. By dialing the code before the telephone number you're calling, you can place the call on a specific long-distance company's line.
When you use a company's lines, note whether the calls are completed as dialed on the first attempt and whether the connection is clear, free of static or echo. If you are not satisfied, you can switch to another long-distance company by contacting your local telephone company.